Fichte characterizes the second part of his Doctrine of Science of 1804 with the term
« phenomenology », to which he assigns a double meaning : theory of illusion (Schein) and
theory of phenomenon (Erscheinung). If the first part of this definition reminds us of Lambert,
the inventor of phenomenology as a philosophical discipline, the second part corresponds to
the idea that Kant has of this discipline, for instance in the Metaphysical Foundations of Natural
Science. Now the question is : is it possible to integrate into a single discipline two concepts
as different as Schein and Erscheinung? If Fichte is successful in uniting both concepts
in his phenomenology, it might be due to the fact that he follows in this the path already
opened by Reinhold in his Beyträge of 1802-1803.